H1000 vs. RL33 vs. IMR 7977

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Mateo, May 2, 2015.

  1. Mateo

    Mateo Well-Known Member

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    H1000 is well known as a cool burning powder. The popularity of the 6.5 SAUM wouldn't be as great if it didn't yield such low pressures/barrel life. But i'm really curious about the new IMR 7977 and if it also carries these cool burning characteristics.
    In Canada we don't have much hope in getting our hands on any IMR 7977. The IMR 4166 is just starting to trickle in.........barely. As for RL33. Im guessing that is the next closest in another brand? This is something I'm hoping someone with QuickLoad will be able to run schematics on. Or better yet, real world testing with the 6.5 SAUM
     
  2. Buttermilk

    Buttermilk Well-Known Member

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    I just shot some IMR7977, H1000, and Retumbo in my 300 RUM on same day trying some different loads.

    One thing I noticed, and I wasn't looking for it, was the IMR7977 seemed to make my barrel hotter than the other two powders.

    I just wished I'd had a temp gun with me to check barrel temperature.

    Interesting that you're in Canada..., the IMR7977 is made in Canada. I guess it has to leave Canada, brought to the USA by Hodgdon/IMR, then get returned to Canada for distribution...
     
  3. Mateo

    Mateo Well-Known Member

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    Yes, it's rediculous. Most here are aware it's a Canadian product. But you guys are many times the market we are. So the product follows the market. One day soon it should start showing up here......
     
  4. Trm82

    Trm82 Well-Known Member

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    I found some 7977 in Canada and tried it in a 7rem and I was not impressed with it. Velocities where a lot slower than retumbo or h1000. I don't think I have any use for it when the other powders work so well. 7977 was 100-150 fps slower .
     
  5. benchracer

    benchracer Well-Known Member

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    Retumbo is a closer alternative than RL-33. I know from some work I have done with .264 Win Mag, using Retumbo and RL-33, that QL has VERY inaccurate load density predictions with RL-33. QL shows RL-33 as taking up less case volume than Retumbo, when it is in fact much coarser grained and takes up considerably more case volume than QL predicts.

    I did find QL predictions for velocity and powder charge with RL-33 to be pretty accurate. When trying to decide if you can get enough of it in the case to make it work, however, don't trust the predicted load density using this powder.
     
  6. Buttermilk

    Buttermilk Well-Known Member

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    In my 300 RUM the IMR7977 was faster and more accurate than H1000. About 60 fps faster.
     
  7. Mateo

    Mateo Well-Known Member

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    Where in Canada are you and where was the powder?
     
  8. CliffM

    CliffM Well-Known Member

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    I found that RL-33 to be quite a bit denser than Retumbo, in fact Retumbo was the least dense of the powders that I have used in my 6.5 Sherman recently.

    Full case to the bottom of the neck:

    72.0= RL-33
    71.0= RL-26
    70.2= IMR7828
    69.0= IMR 7977
    68.5= H1000
    67.5= Retumbo

    Loading the 140 A-Max with:
    IMR7828 62gr= 3196fps IMR7977 61.5gr= 3188fps
    Very close to being identical.
    YMMV

    Cliff
     
  9. benchracer

    benchracer Well-Known Member

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    By weight, you are correct. The problem is that QL volume predictions are inaccurate, meaning that QL predicts charge weights that will not physically fit in the case.
     
  10. elkaholic

    elkaholic Well-Known Member

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    RL33 is definitely the most dense of the extruded powders I have used! I tried one load of 7977 this week when I shot the RL26, and it appears to me that velocity is not going to be as high with it even though I didn't shoot enough to max it out. I really think that RL26 may prove to be a good choice in a lot of cases where RL33 is just a bit too slow. The jury is still out on temp sensitivity, etc., but I got great velocities and very low es even when maxed out. This is something I look for in a powder.....Rich
     
  11. benchracer

    benchracer Well-Known Member

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    Yes, RL-33 is dense, and allows heavier charges than other powders for a given case volume. However, QL underestimates load density by 5-7% with RL-33. I encountered that data discrepancy during recent load development, using Retumbo and RL-33, in my .264 Win Mag. There was enough overall case capacity that RL-33 could still easily be used, but I was getting compressed loads with powder charges that QL was predicting would yield less than 100% load density, even using a drop tube. When going with the smaller capacity "more efficient" cases, there may not be enough space in the case for RL-33 to be utilized, even though QL says it will work.

    Before committing to RL-33 in the smaller cases, it would be wise to fill the case to the base of the neck, using a drop tube, then physically measure the amount of powder in the case, and compare that to the predicted max charge. Even using a drop tube, you will find that you reach higher load densities at lower powder charges, using RL-33, than predicted by QL.

    That load density difference can force powder charges to be lowered enough to erase the potential advantage of using RL-33. In such a situation, I agree that RL-26 may well prove to be the better choice.
     
  12. CliffM

    CliffM Well-Known Member

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    Benchracer,
    I went a different route.

    Full case to the bottom of the neck = QL load density of:

    H1000 = 114.8%
    Retumbo = 113%
    IMR7828SSC = 113%
    IMR7977 = 111.5%
    RL-33 = 108%

    Are we on the same track now.

    Cliff
     
  13. dwm

    dwm Well-Known Member

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    I know it's not an extruded, extreme powder, but Ramshot Magnum has a burn rate similar to H1000 and shoots really well in a 6.5/300WSM. 6.5SAUM is close to 6.5/300WSM.

    It may have an advantage in availability and throat erosion for overbore cartridges as it is a double-based, spherical-shaped powder.

    Something to think about if you can't find anything else ...
     
  14. rgmeddn

    rgmeddn Member

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    Just poking this thread to see if it has any life left.
    Wondering about the claim with IMR 7977 of reduced copper fouling, not to mention the knowledge that may have accumulated in the year + since the last post.